How Can I Tell Whether Previous Electrical Work Was Done Properly?

You usually cannot tell from appearance alone. Proper electrical work should be appropriately certified where required, correctly protected and proven through testing, while fitting sensibly into the rest of the home’s electrical foundation.

If records are incomplete or several owners and electricians have altered the home over time, a licensed electrician can reduce the uncertainty through inspection and testing.

Looking new is not the same as being right

New fittings and a tidy switchboard can create confidence, but they do not reveal every connection, cable or protection decision behind the walls. Equally, older wiring or dated equipment does not automatically prove that previous work was completed poorly.

Electrical standards change over time. WorkSafe confirms that existing installations do not automatically need upgrading simply because newer standards have been introduced, provided the installation is not unsafe.

The useful question is not whether everything looks new. It is whether the work was appropriate when completed, remains electrically safe and is aligned with how the home is being used now.

Start with the paperwork

Ask for any invoices, descriptions of work, Certificates of Compliance, Electrical Safety Certificates and inspection records associated with the property.

WorkSafe states that a Certificate of Compliance should be supplied for fixed wiring work, including the installation of new power points. Routine maintenance, such as replacing an existing socket or light fitting, does not normally receive the same certificate. Certain work involving mains, main earthing or switchboards may also require an independent electrical inspection.

Missing documentation does not automatically mean the work is unsafe. Records may have been misplaced by a previous owner, and some maintenance work may not have required a Certificate of Compliance. However, substantial fixed-wiring work with no clear scope or certification creates a gap worth investigating.

You can also check whether the person responsible was appropriately licensed through the Electrical Workers Registration Board.

Look for consistency and clarity

Without removing covers or touching any wiring, look at what is safely visible.

Well-coordinated work will often have clear circuit identification, securely fitted accessories, appropriate protection and a logical relationship between new equipment and the existing installation. Exposed cables should appear supported and protected, external fittings should suit their location, and junctions should not be left open or accessible.

One untidy label or mismatched power point is not enough to diagnose a problem. More revealing is a pattern of unexplained additions, inconsistent protection, redundant equipment, poorly supported cables or circuits that nobody can clearly identify.

Do not open the switchboard or enter a ceiling space simply to investigate. Electrical workmanship cannot be reliably assessed through a homeowner inspection alone.

Pay attention to how the home behaves

Some problems only become apparent when the system is under load.

Hot or discoloured sockets, recurring circuit-breaker trips, flickering lights, buzzing, crackling or unusual smells all justify further investigation. WorkSafe identifies heat damage, unexplained tripping and flickering as warning signs.

If you notice scorching, crackling or a burning smell around the switchboard, turn off the main switch if it is safe to do so and contact a registered electrical worker.

Testing provides the clearest answer

A proper electrical assessment measures what appearance cannot confirm.

Depending on the concern, an electrician may check circuit identification, polarity, earthing continuity, insulation resistance, RCD operation, protective-device ratings and how the home performs under demand. These checks can reveal conditions that are not visible from the finished surfaces.

There are limits. A non-invasive assessment cannot prove the condition of every concealed joint or cable. However, it can establish a reliable baseline and identify where more targeted investigation is justified.

Consider the whole electrical foundation

A recently replaced switchboard does not confirm that every circuit connected to it is in good condition. Likewise, a neatly installed EV charger, heat pump or solar system may still have been added without fully considering the home’s available capacity or future plans.

Previous work should be considered across Capacity, Protection, Distribution, Condition and Future Ready. Proper work should leave the system safer, clearer and easier to understand, rather than adding another isolated layer to an uncertain foundation.

When is an assessment worthwhile?

It is sensible to get advice when you are buying an older Dunedin home, planning a renovation, adding significant electrical demand, experiencing recurring faults or finding recent alterations with no supporting records.

The aim is not to criticise every earlier decision or modernise everything at once. It is to understand what is sound, what is uncertain and what should be addressed first.

A Power Integrity Review™ can provide that baseline, documenting what can be seen and tested while separating urgent concerns from work that remains acceptable.